October should go to the Xbox, Halo will move a very healthy amount of consoles and PS4 sales might be held back a little by the Cod and Battlefront bundles releasing in November and people waiting for them. A price cut at the end of October for the PS4 is still likely imo, but I think MS will also do something about the X1s price.
So the rest of the year will imo go
October: X1
November: PS4
December: Honestly up for grabs still, depends on how hard MS goes in on holiday deals.